1. Field of the Invention
The present invention relates generally to a light module of a lighting equipment of a motor vehicle and, more specifically, to lighting equipment having one or several light modules.
2. Description of Related Art
Various approaches are known in the art for implementing glare-free high beam without the use of variable speed motors by utilizing special light modules designed as projection systems. To this end, intermediate images are generated from several semiconductor light sources (for example, LEDs) with a primary optics array. Using a lens system, the intermediate images are projected on the road in front of the vehicle so as to generate the resulting light distribution of the light module. For example, such a light module is known from DE 2008 013 603 A1.
Currently, projection modules generate light-dark boundaries as well as dark-light boundaries. Specifically, it is not specified which side of the road should be illuminated. As such, single-lens projection systems can be used only to a limited extent because of their color aberrations. For example, to solve this problem, DE 10 2010 029 176 A1 proposes using achromatic, two-lens systems.
In lens systems, the problem of a chromatic aberration can be avoided by using a reflector as secondary or projection optics. Unlike lens systems, reflector systems have no aberrations, can be produced in a simple and cost-effective manner (especially when large optical areas are required), and do not cause any stray light through Fresnel reflections. However, reflector systems have the disadvantage of developing aperture distortions in larger numeric apertures (for example, different reflector zones have different extensions). Furthermore, in reflector systems, off-axis rays result in a displacement (referred to in the art as “coma”). As a result, a square light source is not represented as a square but rather in the deformed shape of a trapeze or mushroom, wherein size, position and orientation of the image largely depend on the position of the light source in the object field. However, a system generating from multiple semiconductor light sources and having several straight, strictly limited light distributions with definite positions of the individual light-dark boundaries inherently includes imaging properties. Thus, an appropriate total light distribution of a light module needs to be constructed or composed of light source images of the same size and orientation.
In addition, matrix high beam modules known in the art usually use single-chip LEDs, especially SMD (surface mounted device) LEDs in conjunction with a primary optics array. The primary optics array generates intermediate images on the light emitting surfaces of the primary optics elements of the optics array, which are then projected on the road by the secondary optics located downstream in the beam path. Due to the distances between the LEDs, the areas of the intermediate images (referred to in the art as “pixels”) are large, which necessitates using projection lenses with great focal width. Consequently, the resulting light modules are relatively large, which is disadvantageous in motor vehicles because of the relatively limited installation space available for the light modules or the lighting equipment provided with these light modules.
With regard to prior art, in addition to the two above-mentioned publications, reference is also made to the following publications: DE 10 2008 005 488 A1, DE 10 2007 052 742 A1, DE 10 2009 053 581 B3, DE 10 2010 023 360 A1, EP 2 045 515 A1, EP 2 388 512 A2, U.S. Pat. No. 6,758,582 B1 and U.S. Pat. No. 7,055,991 B2.